It's a great irony that I'm spending today working with a client trying to design a system that must be highly available, and simultaneously struggling with my email server becoming unavailable. For added contrast, the problem appears to be with the company that hosts my backup mail servers - a service I pay for in the name of high availability. :p
At any rate, I hope this will get sorted out soon, because at the moment our email is bouncing immediately rather than simply queuing. If you're trying to reach me (or my wife) and you got a bounce, at least now you know what's happening. You can always use my gmail address instead.